The overall objective of this project is to investigate the biology of tooth development. The more immediate objectives, planned for investigation during this project period are: To ascertain the cytological mechanisms of how the cells transport calcium during the mineralization of enamel, cementum and dentin. This will be done by utilization of histochemical procedures for the localization of calcium at the light and electron microscopical level and by the use of experimental models to identify the organelles involved in concentrating calcium.